Automatic pressure-control valve



April 8, 1930. .1. c. SCOVEL, JR 1,753,536

I AUTOMATIC PRESSURE CONTROL VALVE I 2 Sheets-Sheet 1 Filed July 6, 1926lHlul l April 1930. J. c. SCOVEL, JR 1,753,536

AUTOMATIC FIRES SURE CONTROL VALVE Filed July 6, 1926 2 sheets -sheet' 2Patented Apr. 8, 1930 UNITED STATES PATENT OFFICE JOHN C. SCOVEL, JR.,OF CHICAGO, ILLINOIS, ASSIGNOR TO THE CREAMERY PACKAGE MFG. COMPANY, OFCHICAGO, ILLINOIS, A CORPORATION OF ILLINOIS AUTOMATIC PRESSURE-CONTROLvALVE Application filed July 6,

The invention relates to valves for the automatic regulation of theevaporation of the refrigerant in the expansion line of mechanicalrefrigerating systems, more particularly to valves suitable for'suchemploymentin refrigerating systems wherein the relation between pressureand boiling temperature of the refrigerant is utilized to the endthat bycontrolling the pressure of the refrigerant-in the evaporating coils toapproximate uniformity at a predetermined amount, the tem-- perature ofthe refrigerant therein is controlled Within the resultantpre-determined short range, thereby maintaining the desired range oftemperature in, the room or body being cooled.

In refrigerating systems of this type, the liquid refrigerant 'issupplied to the expansion coils or chamber under independent valvecontrol. The liquid is evaporated at a rate proportionate to the degreeof heat being absorbed thereby, and by withdrawing the warmed vapor fromthe expansion coils proportionately to the rate of evaporation in excessof that normal to the predetermined pressure, substantially uniformpressure is maintained within the coils with the consequent relatedtemperature uniformly maintained in the refrigerant.

The withdrawal of the variant excess vapor, and the maintenance ofpredetermined pressure in the coils, may be accomplished by interposinga valve between the expansion coils and the suction side of the compressor, the valve being automatically responsive to variations inpressure inthe coils to release or restrict the escape of the warmedvapor therefrom to the compressor in proportion to the volume evaporatedin excess of that normal to the predetermined pressure.

It is the principal object of this invention to provide an improvedvalve device for the automatic control and regulation of the pressure ofthe refrigerant in the evaporating or expansion coils of a refrigerationsystem, of simple, self-contained structure, easy of adjustment, andeconomical in manufacture.

Other objects and advantages will be apparent in the following detaileddescription 59 of a preferred embodiment of the invention 1926. SerialNo. 120,592.

which I have chosen for illustration in the accompanying drawings. Itwill be understood, however, that various changes in form, constructionand arrangement may be made by those skilled in the art withoutdeparting from the scope and spirit of the invention as expressed in theappended claims. I

Referring to the drawings, Fig. 1 is a sec tional elevation of thedevice. Fig. 2 is a sectional plan taken on the plane of the line 2-2 inFig. 1. Fig. 3 is a sectional plan taken on the planes of theirregularline 33 in Fig. 1. y p v In the drawings, the numeral 1 indicates thebody of a casing enclosing a central chamber 2. A cover. 3 preferablyremovably secured to the body 1 as by cap screws 4, forms a closure atone end of the chamber 2. An oppositely positioned cover 5, alsopreferably removably secured to the body 1 as by cap screws 6, forms aclosure for the other end of the chamber 2. As disclosed herein, thecover 3 is provided with an opening 7 for connection with theevaporating coils on the expansion side of a refrigerating circuit, asindicated by the pipe 8 terminating in open communication with thechamber 2. For

convenience in connecting the device into the piping system, an opening9 is also provided in the side of the body of the casing, which maybealternatelyemployed for the inlet connection from the evaporatingcoils. The opening 9 asherein illustrated is closed by a'screw plug 10.

An outlet opening 11' is provided in the body of the casing forconnection as by a ipe 12 with the suction line leading to thererigerant compressor. The outlet 11 does not" open directly into thechamber 2 but communicates with a passage 13 formed'in a shelf 90 14,preferably integral with the body of the casing and extendin into thechamber 2. The shelf 14 is provi ed with a valve way 15 formedtransversely therein and opening at both ends into the chamber 2. Thevalve'way 15 is in open communication intermediately of its ends withthe passage 13.

Operatively positioned in the valve way 15 is a sleeve valve 16preferably having one end closed and extending normally outward- 10 1yof the valve way. The open end of the valve 16 is provided with a seriesof notches 17. The notches 17 are of such depth that with the valvesleeve 16 moved to innermost position, the passage 13 will be whollyclosed against communication with the chamber 2, and with the outwardmovement of the valve member 16 the notches 17 are moved into registerwith the passage opening, establishing communication'between the passageand the chamber 2.

The shelf 14 is further provided with a lug 18, having a transverse bore19, within which is adjustably mounted a screw threaded support 20having positioning nuts 21 and lock nuts 22 bearing upon either side ofthe lug 18. The support 20 has provided at one end a pivot pin 23 uponwhich is pivotally mounted one or preferably a pair of levers 24. Thelevers 24 are also pivotally connected with the sleeve valve 16 by meansof a pin 25 fixed in a lug 26' formed on the base of the sleeve valve,the pin 25 extending through suitable slots 27, formed in the levers 24.

A diaphragm 28 is secured in the chamber 2, preferably by having itsmarginal edges clamped between the casing body 1 and the cover 5 insealed relation to the chamber 2 and exposed to the pressure of therefrigerant gas within the chamber. The diaphragm 28 is provided at itscenter portion with a plate 29 securely attached to the diaphragm andhaving a pair of bosses 30 extending laterally of the levers 24intermediately of the support 20 and the valve 16, the bosses 30 beingprovided with a cross pin 31 extending through suitable slots 32provided in the levers 24.

Upon the outer side of the diaphragm 28 is provided a plate 33 hearingcentrally upon the diaphragm and securedthereto and to the oppositeplate 29 preferea-bly -by'means of a bolt 34 extending therethrough andinto threaded engagement with the plate 29. The inner face of the outercover 5 is recessed to accommodate the movement of the diaphragm' andits supported attachments. Stops 35 may be provided within the recessfor the abutment of the outer plate 33 to limit the movement of thediaphragm under pressure.

A spring 36 hearing at one end upon the plate 33 and extending outwardlythrough a housing 37 formed on the cover 5, is secured in position by aclosure plug 38 threaded into the outer end of the housing 37. Theadjustable position of the plug 38 enables the antin the evaporatingcoils is imparted adjustment of tension in the spring 36 in oppositionto the pressure sustained by the diaphragm from within the chamber 2.The adjusted position of the plug 38 may be secured by a set screw 39mounted in the wall of the housing 37.

In operation, the pressure of the refrigerthrough the inlet connection 8and the chamber 2 to the diaphragm 28, and as the pressure increaseswith increased evaporation the diaphragm 28 recedes, operating throughthe bosses 30 and levers 24 to withdraw the sleeve valve 16, uncover theport notches, and open communication from the chamber 2 to the passage13. This operation relieves'the excess pressure in the evaporating coilsuntil the reduced pressure in the chamber permits reactance of thespring 36 upon the diaphragm to reverse the movement of the sleeve valve16 and restrict or close communication tothe passage 13. It will beobvious that by adjustment of the tension in the spring 36, by means ofthe plug 38, and by varying the position of the levers 24 throughadjustment of the fixed pivot carried by the adjustably positionedsupport 20, the sleeve valve 16 may be arranged to close at any desiredpressure within a practical range, and by this means limit the lowermosttemperature to be secured by the evaporation of the refrigerant in thecooling coils.

It will be noted that the suction of the compressor, as eflected throughthe suction pi e 12 and passage 13, operates 'to withdraw t e warmedrefrigerant gas, as permitted to escape from the chamber, without effectupon the operation of the valve sleeve 16, as the passage 13 entirelysurrounds the sleeve valve 16 with balanced effect thereupon of whateverpressure there may be in the suction line. It will also be noted thatthe structure herein disclosed is wholly self-contained, the operatingparts being housed within one chamber in a unitary casing, and embodyingsimplicity of structure, easy to adjust and maintain in operativecondition, and economical in manufacture.

I claim as my invention:

1. A device for automatically controlling evaporation pressure in arefrigerant container, comprising a casing enclosing a chamber-having anopen inlet adapted for open communication with said container, a shelfon the wall of said casing extending into said chamber, said shelfhaving a cylindrical transverse valve way opening at both ends into saidchamber and having an enclosed passage communicating with said chamberthrough said valve way, said passage opening outwardly of said casing toform an outlet from said chamber, a cylindrical valve operativelypositioned in said valve way, said valve having constant lateral bearingin said 1 way and having lateral ports adapted to control said passage,a stationary pivot support in said chamber, a lever pivotally supportedon said pivot support and having a pivotal connection with the saidvalve, a diaphragm positioned in said chamber having one side exposed tothe pressure therein, and an operative connection between said diaphragmand said lever whereby said valve is operated by the movement of saiddiaphragm to effect the progressive closing of said passage by alowering pressure in said chamber and to effect the progressive openingof said passage by a rising pressure in said chamber.

2. A device for automatically controlling evaporation pressure in arefrigerant evaporating contalner, comprising a casing enclosing achamber having an open inlet adapted for open communication with saidcontalner, a shelf on the wall of said casing within said chamber, saidshelf having a transverse cylin drical valve way therethrough opening atboth ends into said chamber, said shelf also having an enclosed passagewith a port open ing in said valve way, said passage opening outwardlyof said casing to form an outlet from said chamber, a cylindrical slidevalve havingl constant bearing in said valve way and a apted to controlthe port opening, a pivot support adjustably mounted on said shelf, alever pivotally mounted on said pivot support and having operativeconnection with said valve, a diaphragm mounted in said casing havingone side subjected to the pressure in said chamber, adjustably tensionedresilient means opposingsaid pressure upon said diaphragm, and anoperative connection between said diaphragm and said lever, whereby saidvalve is o erable to effeet the progressive closing 0 said passage by alowering pressure in said chamber and to efiect the progressive openingof said passage by a rising pressure in said chamber.

3. A device for automatically controlling evaporation pressure in arefrigerant evaporating container, comprising a casing enclosing achamber having an open inlet adapted for open communication with saidcontainer, a shelf mounted on. the wall of said casing within saidchamber, said shelf having a transverse valve way. opening at both endsinto said chamber and having an inner peripheral channel formed in saidvalve way, said channel opening outwardly of said casing to form anoutlet from said chamber, a tu bular slide valve operatively positionedin said valve way and controllin said channel,

said tubular valve having en ward notches adapted to open and closecommunication between said chamber and said channel with the movement ofsaid valve member, said valve having constant lateral bearing in saidway to close communication to said channel otherwise than through saidnotches, and means for operating said valve member res onsive to thepressure in said chamber, where y said passage is progressively closedby a lowering pressure in said chamber and is progressively opened by arising pressure in said chamber.

In witness whereof I have hereunto attached my signature. a

J OHN C. SCOVEL, JR.

